Pavement rolling machine

ABSTRACT

A PAVEMENT ROLLING MACHINE HAS A PAIR OF FRONT ROLLS COAXIALLY ALIGNED WITH A FRAME MEMBER THEREBETWEEN AND CENTRALLY LOCATED UNBALANCED SHAFTS IN EACH OF THE FRONT ROLLS WHICH WHEN DRIVEN CAUSE VIBRATION IN THE FRONT ROLLS. A REAR PAIR OF ROLLS IS COAXIALLY MOUNTED ON A COMMON SHAFT WITH A MINIMAL GAP THEREBETWEEN. THE LEFT AND RIGHT SETS OF ROLLS CAN BE DRIVEN INDEPENDENTLY OF EACH OTHER AND THE STRIP OF PAVEMENT WHICH DOES NOT COME IN CONTACT WITH THE FRONT ROLLS DUE TO THE GAP THEREBETWEEN CAUSED BY THE CENTRALLY LOCATED FRAME MEMBER, DOES COME IN CONTACT WITH THE REAR ROLLS HAVING A MINIMAL GAP THEREBETWEEN TO PRODUCE A SMOOTHER PAVEMENT.

P 20, 1971 B. KALTENEGGER 3,605,582

PAVEMENT ROLLING MACHINE Filed Feb. 26, 1970 IN VE N TOR 35mm Km. 754 50 05 BY & fwd; Mm 3J4 United States Patent 3,605,582 PAVEMENT ROLLING MACHINE Benno Kaltenegger, 77/79 Kurhausstr., 5202 Hennef (Sieg), Germany Filed Feb. 26, 1970, Ser. No. 14,360 Claims priority, application Germany, Feb. 28, 1969, P 19 407.5 Int. Cl. E01c 19/28 U.S. Cl. 94-50V 7 Claims ABSTRACT OF THE DISCLOSURE A pavement rolling machine has a pair of front rolls coaxially aligned with a frame member therebetween and centrally located unbalanced shafts in each of the front rolls which when driven cause vibration in the front rolls. A rear pair of rolls is coaxially mounted on a common shaft with a minimal gap therebet ween. The left and right sets of rolls can be driven independently of each other and the strip of pavement which does not come in contact with the front rolls due to the gap therebetween caused by the centrally located frame member, does come in contact with the rear rolls having a minimal gap therebetzween to produce a smoother pavement.

This invention relates to rollingmachines and more particularly to a pavement or road rolling machine useful in producing smooth pavement surfaces.

British Pat. No. 889,701 discloses a pavement rolling machine having four rolls that are designed to engage and smooth fresh pavement. There are two front rolls on the left and right hand sides of the rolling machine respectively and two rear rolls also on the left and right hand sides of the rolling machine respectively. The two front rolls are coaxial with respect to each other as are the two rear rolls and a drive transmission means is provided for driving the front and rear left hand rolls in the same direction forwardly or backwardly and at the same peripheral speed. This same transmission means is capable of driving the front and rear right hand rolls in the same direction forwardly or backwardly at equal peripheral speeds but the right hand front and rear rolls may be driven independently of the left hand front and rear rolls.

The drive transmission means includes a first gear system which may be set to provide either forward or backward rotation of the left hand rolls or may be set in a neutral position. A second gear system which operates independently of the first gear system may be set to provide either forward or backward rotation of the right hand rolls and may also be set in a neutral position. The drive transmission means includes a set of transmission members on the left hand side of the left hand rolls for coupling the first gear system to the left hand rolls and a second set of transmission members on the right hand side of the right hand rolls for coupling the second gear system to the right hand rolls.

The pavement rolling machine described in the above mentioned British patent although highly maneuverable has the disadvantage that there is a substantial gap between the front rolls and an equal gap between the rear rolls. These gaps are in line so that when the road rolling machine is driven along a straight path, there is a wide strip of pavement that is not touched by any of the four rolls. Frequently this strip is even wider if the rotating shafts upon which the rolls are mounted carry unbalanced weights so that the rolls vibrate, thus necessitating support means for the shafts which must be accommodated between both the front and rear rolls.

The present invention provides a pavement rolling machine in which the wide strip of pavement not contacted ice by any of the four rolls is substantially reduced or, under certain circumstances, eliminated.

This is accomplished in the present invention by having only one set of rolls, front or rear, which has an unbalanced shaft. The other set of rolls is mounted on a single shaft whereby the rolls may be rotated closer together so that the width of the strip of pavement left untouched by these rolls is substantially less. Furthermore, it is possible to locate the very limited gap between one set of rolls such that it is not directly behind the Wider gap between the other set of rolls. In this instance, the strip of pavement which is not rolled by one set of rolls, will be rolled by the other set whereby a substantially smoother pavement is obtained.

In accordance with one form of the invention, one set of rolls, front or rear, is mounted on an unbalanced shaft and these rolls have a much thicker rolling surface than the other set of rolls which rotate about a common fixed shaft. Optionally, the first set of rolls having the thicker rolling surfaces may be mounted on two separate unbalanced shafts, one for each of the two rolls, which shafts are coupled together by a clutch such as a clawtype clutch.

Preferably the pavement rolling machine has a frame which surrounds the two sets of rolls and includes an internal bracing structure which is generally T-shaped as seen in plan. The stalk of the T passes between the two vibrating rolls having the thicker rolling surface while the crossarm of the T passes between the two sets of coaxially aligned rolls parallel to their axes.The stalk of the T is preferably circular in cross-section.

Having thus generally described the nature of the invention, particular reference will be made to the accompanying dram'ng illustrating a preferred type of apparatus. The drawing is a plan sectional view of the road rolling machine.

The words front and rear are used for ease of reference and are not to be taken as indicating that the road rolling machine according to the invention necessarily has a front which is different from its rear.

The illustrated road paying machine 1 has four rolls that engage the pavement to compress and flatten it. On the left hand side of the machine, a front roll 2 and a rear roll 4 are provided. On the right hand side of the machine, a front roll 3 and a rear roll 5 are provided. The front rolls are coaxial with one another as are the rear rolls.

The rolls are mounted in a frame 6 comprising side plates 7 and 8, front and rear cross beams 9 and 10 and an internal bracing structure which is generally T-shaped as seen in plan. The stalk of the T is the central vertical plate 34 which passes between the front rolls and the crossarm of the T is parallel to the axes of the rolls and comprises two beams 36 of circular cross-section afiixed to dthe central vertical plate 34 and the side plates 7 an 8.

Drive transmission means (not shown) is mounted on the machine and is designed such that the left hand rolls" 2 and 4 can be driven in the same direction at equal peripheral speeds forwardly or rearwardly while the right hand rolls 3 and 5 can also be driven in the same direction at equal peripheral speeds forwardly or rearwardly, but the right and left hand rolls are driven independently of each other. Thus the drive transmission means comprises two gear systems, one for driving the left hand rolls and the other for driving the right hand rolls, each of which independently of the other can be set for forward rotation or rearward rotation of the associated rolls. Also, each of the gear systems can be set in a neutral position. Gear wheels 11 and 12 are located at the left hand side of left hand rolls 2 and 4 for transmitting power from one of the gear systems to the respective left hand rolls, while gear wheels 13 and 14 are located on the right hand side of right hand rolls 3 and 5, for transmitting power from the other gear system to the right hand rolls. The gear wheels 11, 12, 13 and 14 are rotatably mounted in bearing brackets 15, 16, 17 and 18 respectively which in turn are fixed to the outer end plates 19, 20, 21 and 22 of the rolls 2, 4, .3 and respectively. Ball bearings 50, 51, 52 and 53 in side plates 7 and 8 allow the bearing brackets 15, 1'6, 17 and 18 to freely rotate.

Each of the front rolls 2 and 3 is provided with vibrating means 23 comprising a shaft 24 in one case and 25 in the other case having C-shaped unbalanced weights 29 fixed to them. These shafts are coaxial with the front rolls and are supported by ball bearings 26 mounted in the bearing brackets 15 and 17 and in bearingbrackets 27 and 28 which are fixed to inner end plates 32 and 33 of the front rolls. The bearing brackets 27 and 28 are rotatably supported in ball bearings 35 in the plate 34. A claw-type clutch 30 is provided for releasably coupling the shafts 24 and 25 together. The shaft 25 has an extension to which is fixed a pulley 31 which in turn is driven by a belt (not shown).

The rolling surfaces 2a and 3a on the front rolls 2 and 3 respectively are thicker thanthe rolling surfaces 4a and 5a on the rear rolls 4 and 5 respectively. Thus the front rolls are considerably heavier than the rear rolls necessitating the unusually strong and wide vertical plate 34. Consequently, the gap between the front rolls is unusually wide. The central vertical plate 34 serves to support the adjacent ends of shafts 24 and 25 and the adjacent ends of rolls 2 and 3. The combination of this heavy weight and the vibration generated by the unbalanced weights 29 requires a rigid frame construction at the central location.

The relatively wide gap between the two front rolls 2 and 3 is to be compared with the extremely narrof gap 39 between the rear rolls 4-and 5. The rear rolls contain no vibrator means but rather rotate independently of each other about a common shaft 37 which is fixed in position and is supported at its ends by bearings 38 in bearing brackets 16 and 18. The center of theshaft rotatably supports the adjacent ends of rear rolls 4 and 5 by means of ball bearings 38 in bearing brackets 45 and 46 which are in turn mounted in inner end plates 43 and 44 of the rear rolls 5 and 4 respectively. The shaft 37 is maintained stationary by an extension 37a of the shaft which is fixed in a ring 40 which in turn is fixed in a ring 41 of resilient material. The resilient ring 41 is prevented from rotating by pin 42 mounted on cover plate 48. The two cover plates 47 and 48 cover the gear wheels 11, 12, 13 and 14 and other transmission members (not shown) and form a sealed housing. A further cover plate 49 covers the belt drive for rotating shafts 24 and 25 through pulley 31 to generate the vibration. This same cover plate 49 also covers the rings 40 and 41 and pin 42.

A pavement rolling machine is provided in accordance with this invention which incorporates the advantages of a vibrating roll construction and the advantages of a nonvibrating roll construction whereby the relatively wide strip of pavement which is not rolled due to the wide gap between the vibrating rolls is substantially or completely eliminated by the non-vibrating rolls which have almost no gap therebetween. It is possible to completely eliminate the strip of pavement which does not come in contact with the rolls by constructing either the front or rear pair of rolls such that they are of unequal axial length, thereby the gaps between the front and rear rolls are not in alignment.

I claim:

1. A pavement rolling machine comprising:

(a) a substantially rectangular frame member,

(b) a T-shaped frame having a stalk and crossarm disposed within said rectangular frame member, the

stalk of said T-shaped frame joining one side of said rectangular frame member and the opposite ends of the crossarm of the T-shaped frame joining the opposite sides of said rectangular frame member, said opposite sides being adjacent said one side, and said T-shaped frame comprising substantially heavier material than thematerial of said rectangular frame member,

(0) whereby said rectangular frame member with said T-shaped frame defines first and second areas on opposite sides of the stalk of said T-shaped frame and on one side of the crossarm of said T-shaped frame, and a third area on the opposite side of said crossarm from said one side,

(d) a first pair of rolls, one of said first pair being located in said first area and being rotatably mounted between one of said opposite sides of said rectangular frame member and the stalk of said T-shaped frame, and the other of said first pair being located in said second area and being rotatably mounted between the other of said opposite sides of said rectangular frame member and the stalk of said T-shaped frame,

(e) a second pair of rolls in said third area arranged end to end and rotatably mounted between said opposite sides of said rectangular frame member, the axes of said second pair of rolls being parallel to the axes of said first pair of rolls, and

(f) means to drive each of said rolls of said first and second pairs,

(g) each of the rolls of said firstpair being substantially heavier than each of the rolls of said second pair, and each of the rolls of said first pair including vibrating means for vibrating each roll of said first pair duringrotation, said second pair not including vibrating means.

2. A pavement rolling machine according to claim 1 wherein said first pair of rolls are releasably coupled together by a clutch.

3. A pavement rolling machine according to claim 1 wherein the crossarm of said T-shaped frame is of circular cross-section.

' 4. A pavement rolling machine according to claim 1 in which said second pair of rolls are mounted on a common fixed shaft and said second pair of rolls are independently rotatable.

5. A pavement rolling machine according to claim 1 in which the space between the adjacent ends of the second pair of rolls is not directly in line with the stalk of said T-shaped frame whereby the part of the pavement located between one pair of rolls is contacted by at least oihne roll of the other pair during movement of the mac me.

6. A pavement rolling machine according in claim 5 in whichsaid first pair of rolls are of equal length and said second pair of rolls are of unequal length.

7. A pavement rolling machine according to claim 1 wherein said vibrating means of the rolls of said first pair comprise unbalanced shafts in each roll.

References Cited UNITED STATES PATENTS 127,687 6/1872 Glidden 9450 1,375,185 4/1921 Seiter 20 1,931,766 10/1933 Le Tourneau 9450 3,038,350 6/1962 Meyer 94-50X 3,309,972 3/1967 Peters 94-50 3,318,210 5/1967 Schwamborn 945O 3,415,174 12/1968 Kaltenegger 94-50 3,421,420 1/ 1969 Piatkowski 9450 3,431,832 3/1969 Lang 945O NILE C. BYERS, JR., Primary Examiner 

